Electromagnetic apparatus for separating ores.



No. 634,356. E Patented Oct. 3, |899.

KBEUSEB. ELECTRUMAGNETIC APPARATUS FOB SEPARATING GRES.

on med Feb. 2s, 1899.)

(Applicata NITED STATES PATENT Finca;

EMIL KREUSER, OF MECHERNICH, GERMANY.

SPECIFICATION forming part of Letters Patent No. 634,356, dated October 3, 1899. Application filed February 28, 1899. Serial No. 707,212. (No model.)

To all whom it 71mg/ concern:

Beit known that I, EMIL KREUSER, retired director of royal mines, a citizen of Germany, residing at Mechernich, Rhine Province, Germany, have invented certain new and useful Improvements in Electromagnetic Apparatus for Separating Ores, (for which I have applied for a patent in the following countries, viz: Germany, November 1S, 1898, and Great Britain, February 8, 1899, No. 2,8490 of which the following is a specification.

Foi-"the separation of ores having only a weak magnetic action the only arrangement-s heretofore employed consisted in reducing the sectional area of the magnetic poles to such an extent as by the consequent bringing closely together of the magnetic lines of force so great a concentration thereof was effected as to enable them to attract the weakly magnetizable ore particles. With this arrangement when the ore or mixture of ores treated contains minerals having different degrees of magnetic susceptibilitythe separat-ion thereof has to be effected by successive operations, the materials being made to pass successively through'inagnetic fields having dierent degrees of concentration or generated by electric currents of different strength.

According to the present invention, on the otherl hand, a different method of operating is employed whereby in one and the same apparatus the simultaneous separation of minerals having varying magnetic susceptibilities into 'a corresponding number of separated quantities can be effected, thus affording great advantages both as regards cost of plant and duration of the separating process.

According to this new method no concentrated iields are produced by the reduction of the polar surfaces and only the most concentrated' part of the field used for the ore separation, as was heretofore the case; but by the arrangement of two revolving electromagnet-s with cylindrical polar surfaces placed one above the other a broad field of magnetic lines of force is produced, the strength of which decreases progressively from the middle of the field, where it is strongest, to either side, this entire magnetic iield of varying strength being made operative for the separation of the ores and not only the most concentrated part thereof, as

was heretofore the case. By this means it is rendered possible to effect the simultaneous separation of minerals having different degrees of magnetic permeability in one and the same operation, which feature constitutes the principal advantage of the present invention as compared with the processes heretofore employed.

The method of operating consists in arranging two cylindrical electromagnets one above the other so that in cross-section they present two opposite circular poles of different polarity, as in Figures 1 and 2 of the accompanying drawings, where the upper magnet A is, say, of north polarity, while A is of south polarity. In consequence of the opposite rotation of these poles the iield of magnetic lines of force situated between them receives a peculiar form, the lines of force being bulged outward in the direction of rotation of the magnets, as indicated in the sections at Figs. 3 and fi, where Fig. 3 shows the lines of force when the magnets A A are stationary, while Fig. 4 shows the saine whenv the magnets revolvein the direction of the arrows. The lower part of the said field must, if a cor- .rect separation of the ores is to be effected,

be weakened, which is effected by surrounding it with a tightly-litting cylindrical covering of non-magnetizable material, which must be of a thickness equal'to atleast half the narrowest part of the air-space between the` upper and lower poles, as indicated at Fig. 5, where a is the cylindrical covering of nonmagnetizable material, and the distancep between this and the polar surface A is equal to one-half the total distance between the poles A and A. The covering ci. prevents .the particles of ore resting thereon from being attracted by the lower pole A', so as to adhere to the surface of a; but it does not prevent the passage of the magnetic lines of force through the operative field, and thus it enables the process of fractional separation to be effected in the manner above described. If a particle of ore is delivered onto the lower pole, it will, if at all magnetizable, be attracted by the lupper pole at the point of the smallest air-space, if not earlier in its course. In consequence of the rotation of the poles it then passes into fields of gradually-decreasing y strength, and it will consequently fall away IOO from the upper pole at that point of the circular path where the action of gravit-y overbalances the magnetic attraction. \Vith one and the same kind of ore all the Jfollowing particles will be raised to the same height. A mineral of a less magnetizable nature will be acted upon by gravity at an earlier point of the travel, while amineral having a higher magnetic susceptibility will only fall away at a still greater distance from the point of strongest attraction, and in each case all particles having one and the same degree of magnetic susceptibility will f all away at one and the same point of the path through which it travels.

By the above-described means, therefore, a mass composed of different kinds of ore can be readily separated into its components according to their diiii'erent degrees of magnetic susceptibility.

The exact carrying out of this separating process is dependent upon a correct speed of rotation being imparted to the upper magnetic pole, which determines both the form ofthe magnetic field, as also the path through y which the ore particles fall away in eonsei quence of the momentum imparted to them. 5 In order to preventthe different kinds of ore thus separated by magnetic action from becoming to a certain extent mixed together again in falling, a suitable appliance for intereepting the particles as they fall is a necessary adjunct of the above-described mode of operating. 'lhis is eiiiected by introducing into the operative magnetic tield a series ot' superposed inclined chutes equal in number to the different classes into which the ores are separated, such chutes being made adjustable, so as to enable them to be brought exactly into the correct position for intercepting their particular class of ore.

The aboveedescribed method of operating can be carried out with all electromagnetic oreseparators having two opposite revolving magnets with cylindrical polar surfaces, if such poles be arranged as above described, the lower pole having its magnetic attraction weakened, as before explained, and inclined intercept-ing chutes being introduced into the magnetic field. By its use three, and even four, separate classes of ore can be obtained at one operation.

The new mode of operating will be more readily understood on reference to the accompanying drawings, in which- Figs. l and 2 show two modes of arranging the two cylindrical magnets one above the other. Figs. 3 and t show the tluX of the magnetic lines of force, respectively, with stationary and with revolving magnets. Fig. 5 shows the lower polar surface covered with nou-magnetizable material. Figs. G and 7 show sections of the electromagnetic oreseparators in combination with devices for intercepting and conveying away the separated different kinds of ores.

A is the upper cylindrical magnet, (north pole,) and A the lower one, (south pole.) j) is the distance between the poles. ais the covering of non-magnetizable material tightly surrounding the lower magnetic pole.

The device for intereepting and conveying away the separated ores consists of three chutes C D E, of which the lowest, C, catches the weakest m agnetie materials, D the stronger magnetic 1naterial,and E the strongest magnetic material. The chutes are so arranged as either to be simultaneously adjusted in position in the magnetic field, or each chtite can be separately adjusted, according as may be required by the material acted upon.

The crushed ore is supplied direct onto the covering of the lower magnetic pole either by a chtite B, as at Fig. (3, or byahopper F, with adjustable discharge-opening, as at Fig. 7.

Having thus described the nature ot' this invention and the best means I know of carrying the same into practical effect, l claiml. An electromagnetic ore-separator, consisting of two revolving, cylindrical electromagnets arranged one above the other and having cylindrical polar surfaces, the rotation ot which produces a magnetic field bulged in the direction of rotation, a cylindrical, noninagnetizablc covering tightly fitting the lower cylindrical polar surface to weaken its magnetic attraction relative to that of the upper cylindrical polar surface which raises the ore particles consecutively through polar fields of gradually-decreasing strength, and inclined chutes arranged, substantially as de scribed, to correspond accurately with the several zones of the separated falling ore particles.

2. In electromagnetic oreseparators consisting of two revolving electromagnets with cylindrical polar surfaces the combination ol' two opposite revolving cylindrical polar surfaces arranged one above the other, a tightlyfitting cylindrical covering of non-magnetizable material to the lower cylindrical polar surface to weaken its magnetic attraction relative to that of the upper cylindrical polar surface, and su perposed inclined chutes introduced into the polar field for intercepting and conveying away the different grades of ore as they are separated from each other bythe magnetic attraction of the upper cylindrical polar surface, substantially as described.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

EMIL KREUSER.

Witnesses:

HENRY IIAsPEr., WOLDEMAR HAUPT.

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